The present application relates generally to charging devices and, more particularly, to a system, a charging device, and a method of supplying current to a power storage device.
As electric vehicles and/or hybrid electric vehicles have gained popularity, an associated need to manage delivery of electrical energy to such vehicles has increased. In addition, a need to provide safe and efficient charging devices or stations has been created by the increased use of such vehicles.
At least some known charging stations include a power cable or other conductor that may be removably coupled to the electric vehicle. The charging stations receive electricity from an electric utility distribution network or another electricity source, and deliver electricity to the electric vehicle through the power cable.
In at least some electric utility distribution networks, a plurality of charging devices receive electricity from a common electrical distribution component, such as a transformer. However, if each charging device operates concurrently to supply charging current to an electric vehicle, the current supplied to the electrical distribution component may exceed a rated current limit of the component. In such situations, the electrical distribution component may be damaged and/or a circuit breaker or another protection device may activate to disable power to all charging devices coupled to the electrical distribution component.
At least some known electric vehicle (EV) charging stations or other electric vehicle supply equipment (EVSE) employ a dedicated master control to manage current draw from a group of EVSEs that are connected to the same electrical supply such as a utility distribution network, and are protected by the same overcurrent protection such as main breaker.
Such a conventional master controller or device is typically employed to monitor and control the maximum amount of current an EV charger or EVSE can provide to a vehicle based on the electrical supply the EVSE is connected to.
When some conventional electric utility distribution networks are connected to a plurality of EVSE chargers, particularly when those EVSE chargers are functioning to provide charging currents at or near their maximum ratings, the networks are not able to support all the chargers. For example, if the group of EVSE chargers exceeds the a predetermined current limit for the distribution network, circuit protection devices in the network may trip or open to shut off current flow to the EVSE chargers resulting in no vehicles being charged.
Additionally there is a need for conventional EVSE charging networks to selectively draw current from the distribution network, or provide charging current to a storage device based at least in part on a relative priority that is assigned to an EVSE charger or user.